Here is the start of my "backpack":
Got some aluminum duct stuff from home depot, plus a plastic freezer mug I got from goodwill. We cut the handles off the mug with a handsaw, and sanded down the stumps. Then we cut the aluminum ducts to be as tall as my backpack should be. That part is still in progress, but we drilled copious holes in the scrap segments and put those inside the mugs with battery power christmas lights. Its nowhere near finished, but its definitely a start.
Anyways, I drove back to Missouri today, and was able to share the boxes and bags of scrap pieces with Sam and Crystal. Crystal was pretty busy working on cutting out the pieces for her pleather corset, but Sam couldn't help digging into the pieces and building his gun.
Here is Sam trying on the vest and the coat I brought back, and then with the gun he made in about 2 hours out of the scrap boxes. The only tools required were a pair of tin-snips (loaned to me from dad) and a screw driver. The hose will eventually connect to his back pack. The base of the gun is a flint spark igniter gun that was for my dad's hot air balloon. It still sparks, but dad said it didn't work well enough for him to use, so he donated it.